From owner-svn-src-all@FreeBSD.ORG Mon Dec 28 19:23:40 2009 Return-Path: Delivered-To: svn-src-all@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 8246C10656EF; Mon, 28 Dec 2009 19:23:40 +0000 (UTC) (envelope-from pyunyh@gmail.com) Received: from mail-qy0-f176.google.com (mail-qy0-f176.google.com [209.85.221.176]) by mx1.freebsd.org (Postfix) with ESMTP id D19A38FC17; Mon, 28 Dec 2009 19:23:39 +0000 (UTC) Received: by qyk6 with SMTP id 6so4493297qyk.3 for ; Mon, 28 Dec 2009 11:23:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:received:from:date:to:cc :subject:message-id:reply-to:references:mime-version:content-type :content-disposition:in-reply-to:user-agent; bh=8aIFGzd1sN+Sit4ytpzCxnoOdo47fwwHYsap1AJwkPA=; b=Oc6IlZhWQXvhHBa2mPavdGls2omKFZVlNSMAf4ilNzwJd9jZujPJv6y1HGj1R1Ismo gVfGTKc7k//uW5hhi99df7jJwwp81ufXOZdFB31oWexYriU71tdCvGhxyMBddIUlOB2l BKL7iXIeIRfGy/9kvsUyKDHEx5H+eeSaeIXTs= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=from:date:to:cc:subject:message-id:reply-to:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; b=qx1MhQOPVXpNnJsXGu3Wxg5IxWCr7AhcvRITf/PNyuOD79GKrhdTVrK9DksBqzHIJU mzFq/9niFGvm5zAuMztE6zZMmZHKGc1onVj24yVOXOUiulCiiLF5lov2dgvIxaSrU5Z5 Yz4MKKsUsBe8xC2BrGYhsKRkLvo+30Xrtlo58= Received: by 10.224.127.14 with SMTP id e14mr2568945qas.346.1262028210283; Mon, 28 Dec 2009 11:23:30 -0800 (PST) Received: from pyunyh@gmail.com ([174.35.1.224]) by mx.google.com with ESMTPS id 4sm32354151qwe.35.2009.12.28.11.23.28 (version=TLSv1/SSLv3 cipher=RC4-MD5); Mon, 28 Dec 2009 11:23:29 -0800 (PST) Received: by pyunyh@gmail.com (sSMTP sendmail emulation); Mon, 28 Dec 2009 11:22:18 -0800 From: Pyun YongHyeon Date: Mon, 28 Dec 2009 11:22:18 -0800 To: John Baldwin Message-ID: <20091228192218.GB1166@michelle.cdnetworks.com> References: <200911111913.nABJDewR004319@svn.freebsd.org> <200912281357.04461.jhb@freebsd.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200912281357.04461.jhb@freebsd.org> User-Agent: Mutt/1.4.2.3i Cc: Jack F Vogel , svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org Subject: Re: svn commit: r199192 - head/sys/dev/e1000 X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: pyunyh@gmail.com List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 28 Dec 2009 19:23:40 -0000 On Mon, Dec 28, 2009 at 01:57:04PM -0500, John Baldwin wrote: > On Wednesday 11 November 2009 2:13:40 pm Jack F Vogel wrote: > > Author: jfv > > Date: Wed Nov 11 19:13:40 2009 > > New Revision: 199192 > > URL: http://svn.freebsd.org/changeset/base/199192 > > > > Log: > > With an i386 kernel the igb driver can cause a > > page fault panic on initialization due to a large > > number of bounce pages being allocated. This is due > > to the dma tag requiring page alignment on mbuf mapping. > > This was removed some time back from the ixgbe driver > > and is not needed here either. > > > > Modified: > > head/sys/dev/e1000/if_igb.c > > > > Modified: head/sys/dev/e1000/if_igb.c > > > ============================================================================== > > --- head/sys/dev/e1000/if_igb.c Wed Nov 11 19:00:12 2009 (r199191) > > +++ head/sys/dev/e1000/if_igb.c Wed Nov 11 19:13:40 2009 (r199192) > > @@ -2654,7 +2654,7 @@ igb_dma_malloc(struct adapter *adapter, > > int error; > > > > error = bus_dma_tag_create(bus_get_dma_tag(adapter->dev), /* parent */ > > - IGB_DBA_ALIGN, 0, /* alignment, bounds */ > > + 1, 0, /* alignment, bounds */ > > BUS_SPACE_MAXADDR, /* lowaddr */ > > BUS_SPACE_MAXADDR, /* highaddr */ > > NULL, NULL, /* filter, filterarg */ > > em(4) still has EM_DBA_ALIGN for em_dma_alloc(), but it uses '1' for the align > for RX and TX buffers. Should this specific tag be changed back to using > IGB_DBA_ALIGN or should em(4) be changed to use '1' for em_dma_alloc()? > I think em(4) is right. 82576 GbE datasheet says 16 bytes alignment restrictions for TX/RX descriptors(page 265 and page 284). I remember IGB_DBA_ALIGN was chosen to align on 128 byte boundary to optimize cache line effect because descriptor length should be multiple of 128 bytes. > -- > John Baldwin